I have another few resources somewhere detailing demesne sizes during this time, but I'm not sure where it went. Could probably check wikipedia for sources.
All in all, I'd pull out figures like:
Consider: 6 hundreds, so that's one hundred hides per hundred - 600 hundred hides total, which is around 18000 modern acres ?? or around 48000 old acres if each hide is around 80-120 old acres or 30 modern ones. Assuming it takes 2 modern ?? acres to feed a peasant on wheat for a year, the population of the entire region/county is around 9000. The demesne land, aka the land owned directly by the lord himself and on which his manor/estate lies, is around 1200 modern acres, or 40 hides, so could support around 600 people, including peasants, lord and lord's retinue. The remaining land in the hundred could support around 900 people. Note, acres as stated here refer only to arable farmland, not total size of the region.
